Serious RO/DI question?

[nikonosis]

I bought an rodi on ebay, one of the ones recommened on RC. The TDS was was 0ppm when I got it, around 8 months later the tds was up to 8ppm. I just bought new filters and installed them yesterday. I made some new water last night and I just tested the PPM in it tonight and it was 42ppm. I first thought that maybe the container somehow got something in it so I made a little cup of water and tested it. It read almost 300ppm??? WTH is going on?

These are the filters I bought.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=4436016977&rd=1&sspagename=STRK%3AMEWN%3AIT&rd=1

I didn't get a new RO membrane because I heard they last for a year but going from 8ppm to 42 to 300, something seems weird.
Can anyone help me out?

[nikonosis]

this is the rodi except that its a 100gpd unit if that helps
http://cgi.ebay.com/125-GPD-Reverse-Osmosis-RO-membrane-Water-Filter-Reef_W0QQitemZ4446164926QQcategoryZ20684QQcmdZViewItem

[nikonosis]

update. I flushed the system and now its down to 22ppm. Could my membrane be bad already?

[ScubaTC]

Are you on Middleburg water or well water? I wouldn't think your membrane has gone bad, but have no idea as to the name brand/quality.

Once, I had a membrane that was used for around 4 years. I did 45gal water changes each month and with the auto top-off it was replacing about 6-10gal a day in evap. That's a lot of use and during that time only had to maintain the replacement of my filters to keep the ppm as close to zero as possible.

[ScubaTC]

Maybe you were shipped the wrong size micron filters? We usually try to stay with .5 to 1 micron. I know there are 5 microns out there and maybe even 10 on the sediment.

Just a thought.

[Ikaria]

Talk to Reefkeeps, he should be at the meeting. I know he had that RO/DI, so could probably tell you more.

[PelagicMagic]

your tds meter could be busted. those things are cheap and need to be replaced often

[nikonosis]

<a href=showthread.php?s=&postid=6981263#post6981263 target=_blank>Originally posted</a> by ScubaTC
Are you on Middleburg water or well water? I wouldn't think your membrane has gone bad, but have no idea as to the name brand/quality.

Once, I had a membrane that was used for around 4 years. I did 45gal water changes each month and with the auto top-off it was replacing about 6-10gal a day in evap. That's a lot of use and during that time only had to maintain the replacement of my filters to keep the ppm as close to zero as possible.

its running on well water.

[nikonosis]

<a href=showthread.php?s=&postid=6981472#post6981472 target=_blank>Originally posted</a> by PelagicMagic
your tds meter could be busted. those things are cheap and need to be replaced often

i dunno. ill bring it with me tomorrow if i remember and have rob test it on his rodi water.

[nikonosis]

<a href=showthread.php?s=&postid=6981386#post6981386 target=_blank>Originally posted</a> by ScubaTC
Maybe you were shipped the wrong size micron filters? We usually try to stay with .5 to 1 micron. I know there are 5 microns out there and maybe even 10 on the sediment.

Just a thought.

I don't think so, they look identical to my old ones except i got a clear di filter so i can tell when it goes bad.

[raddogz]

Did you test the first five or so gallons of ro/di water or did you test it afterwards?

When you replace the sediment, and carbon filters you let the system make about five gallons of ro/di water, but you can't use it. If you stick a tds meter in the water it will read some crazy number. The reasoning is that you have to flush that the "additives" for a better lack of words out.

[ScubaTC]

Raddogz is right, I always let mine run for a good while after replacing the filters and the TDS reading is always higher and works it's way back down to zero.

Just a though.. do you still have you old filters. If you know they were running at 8ppm when you replaced them, maybe put them back in to see if your still getting that.... unless they have already hit the trash.

[nikonosis]

i did probably about 4-5 gallons, im gonna try running another 5 and see what happens.

[AZDesertRat]

Whomever recommended that unit to you did you a disservice. Its not a very good RO/DI. If your triubles continue look at a 75GPD Typhoon III from www.airwaterice.com, 75 GPD Premium series from www.buckeyefieldsupply.com, units from www.purelyh2o.com , www.thewaterguys.biz or www.melevsreef.com.
All use top notch components and filters including 75 GPD Dow Filmtec true RO membranes not imported Chinese knockoffs.
RO/DI is not a place to skimp as you have found out the hard way.
Notice the membrane you got does not mention a name and I have tried unsucessfully to contact them asking for a brand. Unfortunately you got what you paid for.

[nikonosis]

<a href=showthread.php?s=&postid=6983892#post6983892 target=_blank>Originally posted</a> by AZDesertRat
Whomever recommended that unit to you did you a disservice. Its not a very good RO/DI. If your triubles continue look at a 75GPD Typhoon III from www.airwaterice.com, 75 GPD Premium series from www.buckeyefieldsupply.com, units from www.purelyh2o.com , www.thewaterguys.biz or www.melevsreef.com.
All use top notch components and filters including 75 GPD Dow Filmtec true RO membranes not imported Chinese knockoffs.
RO/DI is not a place to skimp as you have found out the hard way.
Notice the membrane you got does not mention a name and I have tried unsucessfully to contact them asking for a brand. Unfortunately you got what you paid for.

not really because the tds is going down. i just needed to run about 10g through the new filters. its under 20 now and ive only run about 6 gallons through it. I can buy any kind of membrane i want for the rodi because its made exactly like those expensive name brand ones you are talking about. the same guy that sold me the rodi also sells 75gpd membranes and when this one runs out i will probably get one.

[BeanAnimal]

1). Your membrane is a 100 GPD membrane. That means it is not a TRUE REVERSE OSMOSIS MEMBRANE.

2.) It only has a 90% rejection ratio

3.) It is designed to run at 60 PSI

4) Your DI cartridge is horizontal. This allows channeling and bypassing. A true vertical canister forces the water from the bottom up through the resin. This ensures that the water makes full contact and can not bypass the resin beads.

Call them "expensive units" or whatever your like. The person who recomended that garbage did you a disservice.

With such a high TDS input, you are using A LOT MORE resin than you should due to using the wrong membrane. You are wasting a LOT of water due to the fact that the membrane is designed to be used under higher pressure than household water nornally is. You are still getting HIGH TDS output because your horizontal resin cartridges are undersized and allow the water to channel and bypass.

If they do sell membranes that are NOT DOW FILMTEC made by DOW, then they are not selling good membranes. NOTE: Others use FILMTEC fabric but the membranes are still junk due to their poor construction.

You asked for help, you have all of the information that you need now.

Get a FILMTEC membrane and get a TRUE vertical RESIN canister. You will save yourself a lot fo money in the long run (short term with your TDS).

Bean

[nikonosis]

<a href=showthread.php?s=&postid=6984163#post6984163 target=_blank>Originally posted</a> by BeanAnimal
1). Your membrane is a 100 GPD membrane. That means it is not a TRUE REVERSE OSMOSIS MEMBRANE.

2.) It only has a 90% rejection ratio

3.) It is designed to run at 60 PSI

4) Your DI cartridge is horizontal. This allows channeling and bypassing. A true vertical canister forces the water from the bottom up through the resin. This ensures that the water makes full contact and can not bypass the resin beads.

Call them "expensive units" or whatever your like. The person who recomended that garbage did you a disservice.

With such a high TDS input, you are using A LOT MORE resin than you should due to using the wrong membrane. You are wasting a LOT of water due to the fact that the membrane is designed to be used under higher pressure than household water nornally is. You are still getting HIGH TDS output because your horizontal resin cartridges are undersized and allow the water to channel and bypass.

If they do sell membranes that are NOT DOW FILMTEC made by DOW, then they are not selling good membranes. NOTE: Others use FILMTEC fabric but the membranes are still junk due to their poor construction.

You asked for help, you have all of the information that you need now.

Get a FILMTEC membrane and get a TRUE vertical RESIN canister. You will save yourself a lot fo money in the long run (short term with your TDS).

Bean

I said at the beginning of this thread that i was getting 0 ppm for the first 6 months and then it went up to 8ppm around 8 months. I figured i needed a new di so i just bought all new filters other than the membrane. BTW I can move my di to any position i want. It doesn't have to be horrizontal.

2.) It only has a 90% rejection ratio
emoves 98% to 99.99% of all chemical and harmful dissolved elements and 99% of all bacteria

3.) It is designed to run at 60 PSI
Actually its designed to be run at 45psi.

Tons and tons of people on RC recommend ebay RO+DI units and none of them have had problems with them that I have seen.

[crumbletop]

I don't know where you are getting your numbers. From the link you gave in the OP, they provide a reference range that is 93% (300 ppm in, 20 ppm out). These numbers don't add up to 99%, much less 99.99%. The rejection rate has to do with the RO membrane ONLY, not what comes out after the DI. The whole point of the RO is to reject as much "gunk" as possible to save the DI resin. If you get a RO membrane that lets more stuff through, then you'll get less milage out of your DI resin. The DI is the part that needs replacing most often, and thus maintenance costs will be higher...

Also, one other point that might help you out, the system that you link to contains a GAC filter AFTER the DI to improve taste. Do you have that hooked up? It is probably adding stuff back into your water.

Whew, the grammar on those linked pages is horrid :) -- By their own advertising, you are getting "High technology to deliver the greatest quality water you deserve." Here's hoping your karma isn't all that bad ;)

Jack

[nikonosis]

its down to 8ppm now

[BeanAnimal]

Look you asked for help, and several people have shown you the facts. Choose to listen or choose to ignore, it is your money.

I don't care how many people recomended that unit, it is junk.

You can "turn the resin" any direction you like, it will not fix the inherent design flaw.

Your getting an output of 8 TDS when you should be getting an output of 0 tds!!! Either you are to stubborn to listen or you don't want help.

Your RO MEMBRANE is designed to work at 60-70 PSI, not 45. At 45 PSI the waste to clean water ration increases by a substantial amount and the membrane will not "self flush" as efficiently. This means shorter membrane life.

Did you ask a question to get answers, or to hear yourself talk? Sorry to be rude, but you have done nothing be refute the correct replies with bad information.

Bean

[BeanAnimal]

Refgarding problems withe the "ebay" units....

I already listed them

1) Inferior membrane
A) 90% rejection as opposed to DOW FILMTEC 98%
B) 70 PSI recomended operating pressure as opposed to DOW 50 PSI

2) Inferior resin setup
A) Horizontal resin allows settling, this allows water to flow OVER the bed of resin and bypass it.
B) Horizontal resin does not promote a tight pack and allows the flow to cut channels throug it.

We can list about a half dozen other problemsm, but those are enough right there.

You are living breathing proof of our point. You have a TDS of 8, when it should be 0. You have used up a resin cartridge, when those of us with better units and similar input TDS would still be on the same one. You have asked for help, but turn a blind eye and deaf ear to those that have the real answer.

When you truley want to resolve your problem and save some money, please let me (or somebody else that understands how these units work) help you. I would be more than happy to ehlp you get the most out of the equipment you have with a few simple suggestions on upgrades.

[bbragg]

As noted previously, you probably just needed to flush the membrane. Many are rolled with a preservative in the membrane that needs to be flushed. I usually make 7 or 8 gals before I let the RO dump into the tank. At that point, my input is 235ppm city water and my output is usually about 5ppm.

Also noted, there were some "not true RO" membranes that were 75 or 100gpd. I can't recall the type. I usually stick with 35 or 50 gpd units and run a flush for 10 minutes about 4 times a year. I get pretty good life that way ... plus I use the 1 micron string and 1/2 micron carbon in front if the membrane. That probably helps.

It's a good practice to test your output every once in a while. I've got my RO/DI on a Neptune controller with a float switch. The automation caused me to slack off and one day I noticed a bit of hair algae. My RO died, sucked up all the life in my DI and was basically dumping phosphate laden city water into my tank. I stuck my TDS meter into the stream and it said 580ppm. I nearly passed out. I thought for a minute that I had accidentally put the waste water into the sump.

And, I have seen channeling in horizontal DI. Not good. I would definitely go vertical if at all possible ... as mentioned by the last poster.

My experience may not be typical though. I haven't changed my water in 3 years so I only do evaporative top-off.

[sjm817]

*Bean*
Not to hijack this thread, but I could use some help.
I posted this thread (http://reefcentral.com/forums/showthread.php?s=&threadid=801644) about replacement filters for my Filterdirect unit. I dont want to scrap the whole thing, but replace all the filters to bring it up to snuff. Specific information on parts would be much appreciated.

If you would rather reply to my thread, or reply here, I would appreciate the advice.

TIA

[nikonosis]

are you in marketing for those companies? i understand everything you saying but at the same time I had zero ppm at one point and there are tons of people on ebay that get zero ppm with the ebay units. On melevs site he says anything under 10 ppm is good. Ive seen people with the airwaterice units that don't get zero ppm. I can buy a down filmtec membrane and put it in the unit if i want. I really didn't want to know if i needed a different rodi, i just wanted to know why I was getting 200+ ppm and the problem was answered. The system just needed to run the chemicals out of the new filters i purchased. I do appreciate the help and suggestion though but im really not into spending more money right now on this.

<a href=showthread.php?s=&postid=6987505#post6987505 target=_blank>Originally posted</a> by BeanAnimal
Refgarding problems withe the "ebay" units....

I already listed them

1) Inferior membrane
A) 90% rejection as opposed to DOW FILMTEC 98%
B) 70 PSI recomended operating pressure as opposed to DOW 50 PSI

2) Inferior resin setup
A) Horizontal resin allows settling, this allows water to flow OVER the bed of resin and bypass it.
B) Horizontal resin does not promote a tight pack and allows the flow to cut channels throug it.

We can list about a half dozen other problemsm, but those are enough right there.

You are living breathing proof of our point. You have a TDS of 8, when it should be 0. You have used up a resin cartridge, when those of us with better units and similar input TDS would still be on the same one. You have asked for help, but turn a blind eye and deaf ear to those that have the real answer.

When you truley want to resolve your problem and save some money, please let me (or somebody else that understands how these units work) help you. I would be more than happy to ehlp you get the most out of the equipment you have with a few simple suggestions on upgrades.

[frank2926]

You did NOT get a new Ro membrane....correct?

Then their is nothing to flush out of a new sediment and carbon block....well I maybe their is from made in taiwan filters off ebay.

I hear Deltec is making an RO unit just for you.

[nikonosis]

<a href=showthread.php?s=&postid=6988912#post6988912 target=_blank>Originally posted</a> by frank2926
You did NOT get a new Ro membrane....correct?

Then their is nothing to flush out of a new sediment and carbon block....well I maybe their is from made in taiwan filters off ebay.

I hear Deltec is making an RO unit just for you.

sounds good:rolleye1:

[BeanAnimal]

NO I have nothing to do with any of these companies.

You asked a question and I gave an answer. It does not matter what TDS Melev says is acceptable (he may even be correct, but the acutal number is moot with regards to the point being made here and is really a personal comfort level.). A properly working RO/DI unit will have 0 TDS output, not 8. The reason that the output of your unit is 8 and not 0 are due to the reasons listed above.

The major point to take away from this is rather simple: Lets leave the memrane and it's efficiency out of the equation.

If your resin was working properly, it would take care of what the membrane missed, it is that simple.

The other points were more directed to the cost of operation (poor rejection membrane = more resin usage, and higher rated op pressure = more substantialy more waste water).

You want to monitor the TDS of th RO water to determine how well the membrane is working. As stated, you do need to flush a new membrane due to the oils used to preserve it during it's shelf life.

Bean

[frank2926]

I didn't get a new RO membrane because I heard they last for a year but going from 8ppm to 42 to 300, something seems weird.

He did not replace his membrane. So he is just another example of the good ole ebay unit

[BeanAnimal]

Without knowing the TDS of hte RO water, it is hard to say exactly what problems he was having. However it sounds like either a bad post filter (after the DI) or the Membrane is shot, and the DI is exhausted, or bypassing a LOT of stuff.

The first thing I woul do would be to check the RO TDS, if it is within reason, then I would replace the DI with a vertical housing nad new resin.

Honestly, this is a broken record thread (no offense to the OP) but many of hte eBay units are just garbage. You really do get what you pay for with regards to the operating cost and quality of these things. This is not rocket science of voodoo. It is very easy to show exactly why some units are better than others and to quantify why some units cost more to operate than others.

This thread and the OPs problems are a prime illustration.

If you can get back to us with the RO TDS it would help us help you greatly. Also get us a TDS (again) of your input water and the final product water. From those numbers we may be able to track down your problem (other than the fact that your DI is simply not doing it's job).

[nikonosis]

what is a decent ro reading? ill check it later today.

<a href=showthread.php?s=&postid=6990511#post6990511 target=_blank>Originally posted</a> by BeanAnimal
Without knowing the TDS of hte RO water, it is hard to say exactly what problems he was having. However it sounds like either a bad post filter (after the DI) or the Membrane is shot, and the DI is exhausted, or bypassing a LOT of stuff.

The first thing I woul do would be to check the RO TDS, if it is within reason, then I would replace the DI with a vertical housing nad new resin.

Honestly, this is a broken record thread (no offense to the OP) but many of hte eBay units are just garbage. You really do get what you pay for with regards to the operating cost and quality of these things. This is not rocket science of voodoo. It is very easy to show exactly why some units are better than others and to quantify why some units cost more to operate than others.

This thread and the OPs problems are a prime illustration.

If you can get back to us with the RO TDS it would help us help you greatly. Also get us a TDS (again) of your input water and the final product water. From those numbers we may be able to track down your problem (other than the fact that your DI is simply not doing it's job).

[BeanAnimal]

For a DOW filmtec 75 GDP membrane, 2% TDS is good (some people get even less).

For a GER DESAL membrane or DOW 100 GPD membrane a 10% TDS reading is within specs.

So if your INPUT water is 200 TDS then the DOW FILMTEC should output someplae around 2 TDS, the GE DESAL someplace around 20 TDS. Other "filmtec knock offs" anywhere from 25 TDS to 10 TDS would be expected.

Bean

[sjm817]

<a href=showthread.php?s=&postid=6987654#post6987654 target=_blank>Originally posted</a> by sjm817
*Bean*
Not to hijack this thread, but I could use some help.
I posted this thread (http://reefcentral.com/forums/showthread.php?s=&threadid=801644) about replacement filters for my Filterdirect unit. I dont want to scrap the whole thing, but replace all the filters to bring it up to snuff. Specific information on parts would be much appreciated.

If you would rather reply to my thread, or reply here, I would appreciate the advice.

TIA
Please?


Basically, I have a FD unit and I want to replace needed parts to get it up to snuff. I assume a good 75GPD Fimtec and vertical DI would do it? How about the prefilters? This is a 6 stage unit with the home drinking water option. Any difference between what AWI and Buckeye FS sell?

Thanks!

[BeanAnimal]

Your prefilters should be fine. Replace them every 6 months, or every time you replace DI resin (whichever comes first).

What is your input TDS? This will dictate if it is "worth" prematurely upgrading the MEMBRANE. The vertical DI canister is a must. Get one from a reputable vendor and have them pack it for you (buckeye or AWI, or even melev). This is the single most important thing you can do to ensure 0 TDS output. If you have high TDS input, then yes a new membrane will greatly extend the life of your resin.

Bean

[sjm817]

Thnx for the reply. I just took a look. First of all, I have 2 TDS meters. Admittadly, neither have ever been calibrated, so I know that is an issue.

I have a handheld:
http://www.premiumaquatics.com/aquafx/tds_iii_meter.jpg

And a dual inline connected input before and output after the DI.
http://www.premiumaquatics.com/images/TDSInLine.gif

The tap water reads 189 with the handheld
If I make up some water, the inline starts with the input ~ 8 and the output ~4. After it runs a little while, the input and output both go to 1. The handheld reads 4 on the DI output, so there is a discrepancy.

Dumb question:
Would it make a difference if the normal horizontal DI is mounted vertically? Input on the bottom, output on the top?

[BeanAnimal]

It mayhelp a little bit to orient the DI cartridge in that fashion. However, you will find that due to the packing method and size of the cylinder, the water will tend to still bypass the resin. It can't hurt to try though!

[sjm817]

How about my TDS readings? Good/bad/inconclusive?

[BeanAnimal]

Youyr inline meters do not sound to accurate. It is not likely that a 90% membrane will output 1 TDS water with an input 0f ~200

That leads me to believe the handheld is more accurate. Which also shows that your DI is not doing it's job. The output should be closer to ZERO. Does your unit have an RO only output? Test that with the handheld.

[sjm817]

The drinking water is RO without the DI and goes through an extra carbon filter. That is a TDS of 5 with the handheld. Both the inline and handheld show little difference in RO Vs DI. The 189 TDS is right out of the faucet, and doesn't touch the RO/DI system at all. I dont know what the TDS is going in to the RO membrane (TDS drop from prefilters). I'd have to do some work to get a measurement there.

[ohioreef]

I have a filterdirect unit and it is far from, as you call it, junk!! I did get mine with the 75gpd membrane and replaced the horizontal DI with a full size vertical DI and have been very very pleased and I spent significantly less than your "name brand" models.

[BeanAnimal]

I am not interested in the arguement... either you are trolling or misinformed. Where in this thread did I use the work JUNK? Either way, this is a weekly deal around here and starting to get old.

If you disagree with the facts above, then please explain why and show where my facts are incorrect. You have a "filterdirect" unit, that has been "customized" and is therefore not the same price or performance level as the typical "ebay" unit.

I can buy a jeep and put a bigblock in it, that surely does not make jeeps fast or powerful.

You state you have a 75GPD membrane, is it a DOW FILMTEC or GE DESAL, OR WORSE, an overseas knock-off with filmtec fabric?

You state you replaced your DI, how much did you pay? Is your unit 5 stage, or smaller?

In other words it appears you jumped right in here to troll for a fight, but really have not offered anything other than a vague statement. Sorry to be so blunt, but as I stated, this arguement seems to be a weekly ordeal. The outcome is always exactly the same. The "pro Filterdirect" folks make all kinds of accusations and misinformed statements, only to shown why they are incorrect.

The price difference between the "name brand" and the "filterdirect" is $100. Most of that cost is the difference in MEMBRANE, DI RESIN, DI HOUSING. The remaining few dollars of difference is in valves and fittings that make the unit more convenient. Customer service is something to consider (may or may not have value to certain people) and the "overall" quality of the supporting components and assembly. It is a know fact that a large percentage of the FD units come plumbed incorrectly or with VERY LEAKY fittings. (not a problem for some folks, a nightmare for others).

Honestly ohio, what exactly do you want to fight about and why bother? I am trying to help people get the most out of what they have or spend their money wisely. If you feel insulted that your unit gets critical reviews, then I am sorry, but the facts speak for themselves.

[ohioreef]

Honestly, this is a broken record thread (no offense to the OP) but many of hte eBay units are just garbage.

I'm sorry, you said they were garbage, not junk..... :rolleyes:

FYI, I am not trolling nor trying to start a fight. It gets so old hearing people coming in here and saying that you have to purchase the name brand units! I did my research before purchasing my filterdirect unit and I knew what I was getting. Yes mine has been "customized", but I still have less in my set-up than I would for a comparable "name-brand" unit.

As a comparison: an AWI 75gpd is $199 for the unit, http://www.airwaterice.com/product/1DUALHR, comparable to my filterdirect. My filterdirect, http://cgi.ebay.com/RO6100-DI-2-output-RO-DI-Drinking-Aquarium_W0QQitemZ7729024961QQcategoryZ46310QQtcZphotoQQcmdZViewItem, was $115 plus the DI at $40 for a total of $155, a savings of $44. I did request the 75gpd membrane. The membrane is a Filmtec membrane.

According to the current listing, the filterdirect units come with the GE Desal membranes.

Some people can afford to buy the name brand units and if you sleep better at night, fine, it's your money. Some people can not afford the "name brand" units and look to the less expensive units. I just feel that totally dismissing the ebay units as being no good is doing a disservice. Like everything else in this world, caveat emptor, you need to know what you are getting.

You seem to be blatantly bashing the ebay units rather than "relaying information."

[BeanAnimal]

There are several problems.

Firstly, the "ebay" units are advertised in such a way that they "look better" than the name brand units. The ads have BLATANT falsehoods and severely misrepresent the capablities of the units. They List "FILMTEC" membranes but not the DOW units, instead they pawn off cheap imitations that simply use dow fabric. They point blank say that the GE DESAL membrane us being used because it is better, then paste a bunch of irrelevant numbers. Dishonesty in the part of the vendor warrent some kind of scepticism (bashing if you prefer).

Secondly, the average buyer has no idea what constitutes a good RO/DI unit. They are led to believe that those crummy undersized horizontal DI stages are superior and that "stages" is better than the other guys 5 stages! We already covered the lies about the membranes.

Many people have no idea how these units work, let alone how to assemble, troubleshoot or repair these units. The Filterdirect comes with questionable support (from dozens of accounts), little or no instructions, and in many case no or incorrect assembly.

Also, affordability is directly related to the performance of such a unit, just as gas mileage and maintenance are directly related to owning a car. This point seems to get whitewashed time and time again.

Because the "ebay" units use membranes with poor rejection ratios that are rated to run at high pressure, the DI usage and water waste add up very quickly. This is a real cost and has everything to do with the quality of the unit.

As you stated yourself, the difference was $44. Piece of mind may be worth that to some. The customer support may be worth that to others. The extra attention to detail to yet others. If you have a true DOW FILMTEC membrane and quality resin, then you can expect the same performance as my name brand unit. You may not have all the features (or may) and you may not need the support or the better quality fittings, housings, brackets or pre-filters. However most folks do (or don't know any better).

You will find person after person here on RC every week that has a Filterdirect unit and singing with glee that they have an output TDS of 10! They just assume that 10 is good, because they unit is good and those of us who say it isn't are infatuated with brand names.

Bashing? Maybe I am but not without solid evidence and good intentions. Most of the ebay units (there are some good vendors) are simply poor imitations of quality products, you yourself at least knew enough to upgrade your unit to the bare minimum for suitable performance.

:)

[ohioreef]

You've made some valid points, but like any purchase the buyer needs to do the research so they know what they are getting.

FWIW, I'm getting about 97% rejection rate from my membrane, however that is on a well water system where the maximum pressure is 40psi and the temp around 60 degrees. I suspect I'd get better performance if I used a booster pump.

[BeanAnimal]

The rejection rate will not change much, but the waste water will decrease (the higher the pessure, the more water the membrane can process). Temperature has the same effect, warmer water works better, but if it is to warm, the TDS at the output will rise.

Bean

[nikonosis]

BeanAnimal,

So would you buy this
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7727978274&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1

or would you pay an extra $11+ shipping from www.airwaterice.com for the same thing?

[ohioreef]

I would think that as long as you receive the membrane pictured it would be fine. It is a Filmtec membrane which are supposed to be good.

Heck, it says he has a 30-day return guarantee. Can't see where you'd go wrong.

The same membrane is $45 at buckeyefieldsupply.com.

[BeanAnimal]

Yes that is a DOW FILMTEC. PurleyH20 is a reputable dealer with a great product. He is a member here at RC as well.

[ohioreef]

So not ALL ebay dealers' products are garbage!! :D















Sorry....couldn't resist!! :smokin:

[BeanAnimal]

Nope, there are some good people out there that are honest with their ads and honest with their customers. PurelyH20 seems to be one of them. I have never dealt with him, but know others who have. His units are about the same as the other quality brands mentioned, good membranes, housings, filters, resins, fittings and other parts.

Bean

[twkenny]

I've dealt with him on several occasions and have referred several people to him. Very good products and customer service. Always willing to help.

Just a little added info...
Bryan (www.purelyH2O.com) has a regular store in Orlando as well. He's not just a web/ebay guy.

[warden13]

Can anyone recommend a name brand (not the e-bay units) RO/DI system that contains the drinking water system (tank, faucet, etc.) for around $200? It seems like you can get a quality RO/DI unit for around $200 but when you piece together the drinking water add-ons + shipping = $300 plus. :eek1:

[ohioreef]

Buckeye Field supply has a "value line" 75gpd RO/DI system, http://www.buckeyefieldsupply.com/showproducts.asp?Category=167&Sub=166, for $118. Their drinking water add on is $87.99, http://www.buckeyefieldsupply.com/showproducts.asp?Category=165&Sub=103. That gets you close.

[AZDesertRat]

www.purelyh2o.com has a drinking water system for $165 and an add on DI system for $27. About the same. www.airwaterice.com has the Dual Home/Reef for $189 or $199 with the 75 GPD membrane.
There are lots of good ones out there but I think the 3 suggested are about as good as they come. You might also check out www.thewaterguys.biz, they probably have something close too.